Image sensors are commonly used to obtain an image of an object, e.g., a physical document or a form, for processing markings of the object. For example, circuitry of the image sensor or in communication with the image sensor converts markings of the obtained image into data that can be machine-processed. Example forms of which an image is obtained for processing of markings in the image are lottery playslips. An example playslip is a card, ticket, or other printed media that indicates a player's lottery number selections. It may be used by the player to purchase a lottery ticket having the indicated player lottery number selections. Markings of the lottery playslips are processed, e.g., for determining numbers selected by a player for an upcoming lottery drawing.
It is conventional to use a linear image sensor to obtain the image for processing of markings of the image. For example a linear barcode scanner is used to obtain an image of a portion of a barcode, i.e., a representative line of the barcode. Individual sub-markings of the obtained line are converted into processable data in order for a processor to “read” the barcode. Barcode scanners are commonly used in lottery applications.
Where lines to be processed are not uniform, so that one line of markings is not representative of all other lines of markings, it is necessary for the linear image sensor to progressively obtain a plurality of images, for example, one image per line. To do so, it is conventional for a user to tediously pass a hand-held linear image sensor over the object until all of the lines of the marking are obtained by the linear image sensor. The use of such linear image sensors to obtain an image that includes a number of non-uniform lines of markings to be processed takes up much time and effort by the user.
It is also conventional for a linear image sensor to include a mechanical device either for passing the linear image sensor over the object or for passing the object by the linear image sensor. Such sensors are bulky, and the use of such linear image sensors takes up much time.
Furthermore, some forms include markings, the processing of which is in accordance with a position of the markings with respect to the form. To process such markings, it is conventional to provide a linear image sensor with an electro-mechanical device to precisely position the form in a predetermined position with respect to the linear image sensor and to pass the form so positioned over a readhead of the linear image sensor. Since the form is positioned in a predetermined manner, a processor can process markings of the form according to the location of the markings in the precisely positioned form. For example, some lottery tickets, e.g., lottery playslips often include geometric shapes to be filled in by a user, e.g. fill-in squares, circles, etc. Each filled-in shape is processed as a particular number based on a position of the mark with respect to the ticket. It is conventional for an electro-mechanical device to pass such playslips over a readhead of a linear image sensor in order to obtain an image of the playslip for processing of the fill-in markings, for example as number selections for a lottery drawing. However such electro-mechanical devices are expensive.
It is conventional to use an area-array image sensor to simultaneously obtain an image of numerous lines of a form, e.g., to simultaneously obtain all fill-in markings of a lottery playslip. However, an image of the same form sensed by the area-array sensor may vary depending on the form's position with respect to the area-array sensor. For example, for a particular sensing area sensed by the area-array sensor, the sensed image of the form consumes much or all of the sensing area when the form is positioned near the area-array sensor, and consumes less of the sensing area when the form is placed farther from the area-array sensor. Differences in the degree of tilt of the form with respect to the area-array sensor also result in differences in the image sensed by the area-array sensor. For example, if a top side of a rectangular form is tilted away from the area-array sensor, the sensor senses the form as though it is of a trapezoidal shape, such as that of the form image 100 illustrated in FIG. 1. Since a change in the form's position or degree of tilt produces a change in the image sensed by the area-array sensor and therefore distorts the processing of the markings of the form, it is conventional to provide a stand in which to place the form, e.g., the playslip during image capture, so that the playslip is positioned in a predetermined manner with respect to the area-array sensor. However, such stands take up space, e.g., counter space at a lottery terminal.